Distribution of P2X receptors on astrocytes in juvenile rat hippocampus
Distribution of P2X receptors on astrocytes in juvenile rat hippocampus
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作者：
Kukley, M;Barden, JA;Jabs, R
最近的证据表明，ATP通过嗜离子性（P2X）和代谢性（P2Y）嘌呤能受体可能参与神经胶质细胞之间和神经胶质网络内的信号传导。与它们的神经元对应物相反，P2X受体在中枢神经系统胶质细胞中的身份在很大程度上是未知的。本研究采用识别P2X(1)-P2X(7)亚基的抗体，结合星形胶质标记物S100 β和Hoechst 33342核标记，半定量地研究了P2X受体在幼年大鼠海马星形胶质细胞中的分布。在海马各亚区星形胶质细胞中均可见P2X(1)-P2X(4)、P2X(6)和P2X(7)亚基的表达，但这些细胞完全缺乏P2X(5)蛋白。表达P2X(3)-P2X(7)亚基的S100 β阳性细胞均匀分布在不同亚区，而P2X（1-）和P2X(2)阳性星形胶质细胞分布更为不均一。在亚细胞水平上，P2X亚单位的染色模式也存在差异。抗P2X(2)和P2X(4)的抗体标记星形胶质细胞体和突起。P2X(1)和P2X6的免疫反应性主要局限于S100 β阳性细胞的体细胞区域，而P2X(3)亚基主要定位于星形胶质突起。了解P2X受体的分布可能为更好地理解它们在细胞-细胞信号传导中的特定作用提供基础。Wiley-Liss, Inc.
Recent evidence suggested that ATP acting via ionotropic (P2X) and metabotropic (P2Y) purinergic receptors might be involved in signaling between glial cells and within glial-neuronal networks. In contrast to their neuronal counterpart, the identity of P2X receptors in CNS glial cells is largely unknown. In the present study, antibodies recognizing the subunits P2X(1)-P2X(7) were applied together with the astroglial marker S100 beta and nuclear labeling with Hoechst 33342 to investigate semiquantitatively the distribution of the whole set of P2X receptors in astrocytes of the juvenile rat hippocampus. Expression of P2X(1)-P2X(4), P2X(6), and P2X(7) subunits was observed in astrocytes of various hippocampal subregions, but the cells were completely devoid of P2X(5) protein. S100 beta -positive cells expressing subunits P2X(3)-P2X(7) occurred evenly in the different subfields, while P2X(1-) and P2X(2)-positive astrocytes were distributed more heterogeneously. The staining pattern of P2X subunits also differed at the subcellular level. Antibodies against P2X(2) and P2X(4) labeled both astroglial cell bodies and processes. Immunoreactivity for P2X(1) and P2X6 was mainly confined to somatic areas of S100 beta -positive cells, whereas the subunit P2X(3) was primarily localized along astroglial processes. Knowledge of the distribution of P2X receptors might provide a basis for a better understanding of their specific role in cell-cell signaling. (C) Wiley-Liss, Inc.